stickers: bridge LINE stickers as m.sticker at LINE's display size

pkg/connector/handlers/sticker.go

@@ -1,10 +1,13 @@
 package handlers
 
 import (
+	"bytes"
 	"context"
 	"encoding/binary"
 	"fmt"
 	"hash/crc32"
+	"image"
+	_ "image/png"
 	"io"
 	"strings"
 
@@ -14,7 +17,7 @@ import (
 	"github.com/beeper/line/pkg/line"
 )
 
-// ConvertSticker converts a LINE sticker message to a Matrix image or text fallback.
+// ConvertSticker converts a LINE sticker message to a Matrix sticker or text fallback.
 func (h *Handler) ConvertSticker(ctx context.Context, portal *bridgev2.Portal, intent bridgev2.MatrixAPI, data line.Message, relatesTo *event.RelatesTo) (*bridgev2.ConvertedMessage, error) {
 	stkID := data.ContentMetadata["STKID"]
 	stkTxt := data.ContentMetadata["STKTXT"]
@@ -77,23 +80,28 @@ func (h *Handler) ConvertSticker(ctx context.Context, portal *bridgev2.Portal, i
 
 				bodyName := "sticker." + ext
 
+				info := &event.FileInfo{
+					MimeType: mimeType,
+					Size:     len(stkData),
+				}
+				if cfg, _, err := image.DecodeConfig(bytes.NewReader(stkData)); err == nil {
+					info.Width = cfg.Width * 2 / 3
+					info.Height = cfg.Height * 2 / 3
+				}
+
 				mxc, file, err := intent.UploadMedia(ctx, portal.MXID, stkData, bodyName, mimeType)
 				if err != nil {
 					h.Log.Warn().Err(err).Msg("Failed to upload sticker to Matrix")
 				} else {
 					return &bridgev2.ConvertedMessage{
 						Parts: []*bridgev2.ConvertedMessagePart{
 							{
-								Type: event.EventMessage,
+								Type: event.EventSticker,
 								Content: &event.MessageEventContent{
-									MsgType: event.MsgImage,
-									Body:    bodyName,
-									URL:     mxc,
-									File:    file,
-									Info: &event.FileInfo{
-										MimeType: mimeType,
-										Size:     len(stkData),
-									},
+									Body:      bodyName,
+									URL:       mxc,
+									File:      file,
+									Info:      info,
 									RelatesTo: relatesTo,
 								},
 							},

pkg/connector/send_message.go

@@ -131,7 +131,9 @@ func (lc *LineClient) HandleMatrixMessage(ctx context.Context, msg *bridgev2.Mat
 	// Matrix clients often send media as MsgFile (e.g. drag-and-drop), which would otherwise
 	// be sent as ContentFile (14) instead of the appropriate media type on LINE.
 	effectiveMsgType := msg.Content.MsgType
-	if effectiveMsgType == event.MsgFile && msg.Content.Info != nil {
+	if effectiveMsgType == event.CapMsgSticker {
+		effectiveMsgType = event.MsgImage
+	} else if effectiveMsgType == event.MsgFile && msg.Content.Info != nil {
 		mime := msg.Content.Info.MimeType
 		if strings.HasPrefix(mime, "audio/") {
 			effectiveMsgType = event.MsgAudio

pkg/connector/userinfo.go

@@ -46,7 +46,7 @@ func (lc *LineClient) HandleMatrixReadReceipt(ctx context.Context, read *bridgev
 
 func (lc *LineClient) GetCapabilities(ctx context.Context, portal *bridgev2.Portal) *event.RoomFeatures {
 	caps := &event.RoomFeatures{
-		ID:               "dev.highest.matrix.line.capabilities.2026_10_14",
+		ID:               "dev.highest.matrix.line.capabilities.2026_10_21",
 		MaxTextLength:    5000,
 		Reply:            event.CapLevelFullySupported,
 		Reaction:         event.CapLevelPartialSupport,
@@ -81,6 +81,16 @@ func (lc *LineClient) GetCapabilities(ctx context.Context, portal *bridgev2.Port
 					"image/jxl":     event.CapLevelFullySupported,
 				},
 			},
+			event.CapMsgSticker: {
+				Caption: event.CapLevelRejected,
+				MaxSize: handlers.BeeperMaxFileSize,
+				MimeTypes: map[string]event.CapabilitySupportLevel{
+					"image/png":  event.CapLevelFullySupported,
+					"image/gif":  event.CapLevelFullySupported,
+					"image/webp": event.CapLevelFullySupported,
+					"image/jpeg": event.CapLevelFullySupported,
+				},
+			},
 			event.MsgFile: {
 				Caption: event.CapLevelRejected,
 				MaxSize: handlers.BeeperMaxFileSize,